Prospective interventional study of tenofovir in pregnancy to prevent vertical transmission of hepatitis B in highly viremic women.

Background The risk of vertical transmission of hepatitis B virus (HBV) increases as maternal HBV DNA increase, despite serovaccination to newborns. Methods From 1 July 2012 to 1 January 2016, all pregnant women in Lariboisiere Hospital, Paris, France, with HBV DNA of 5 log(10) IU/ml and above were administered tenofovir from week 28 of pregnancy until delivery. HBV DNA was measured at months 1, 2 of tenofovir and at delivery. The newborns were serovaccinated, tested for hepatitis B surface antigen, hepatitis B core antibody (HBcAb) +/- HBV DNA, and hepatitis B surface antibody (HBsAb) when aged 9 months, and then 24 months. This study was registered in http://www.ClinicalTrials.gov (NCT02039362). Results Thirty-one women gave birth to 37 newborns. Maternal HBV DNA at baseline was 8.23 log(10) IU/ml and above in 12 pregnancies. The mean (median) HBV DNA were 4.4 +/- 1.2 (4.8), 3.3 +/- 1.7 (3.8), and 2.1 +/- 1.9 (2.0) log(10) IU/ml at months 1, 2 of tenofovir and at delivery, respectively. Twenty-seven newborns were followed up: none of the 19 children aged 9 months or older was positive for hepatitis B surface antigen when aged 9 months; 14 children tested positive for HBcAb (probably transferred maternal antibodies, not found when aged 24 months) and for HBsAb without HBV DNA. Four of the 19 children showed HBsAb without HBcAb, the last being doubtful for HBcAb and HBsAb without HBV DNA. Eight newborns aged less than 9 months were not tested. Conclusion Tenofovir from week 28 of pregnancy to highly viremic HBV women plus serovaccination to newborns could prevent chronic and past infection. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.